Abstract Two metallic calorimetric cells with different geometry, one cylindrical and the other rectangular, manufactured in steel, with an approximate capacity of 300 mL, were tested. The behavior of the two cells was studied under different isolation, energy source, and calorimetric liquid conditions. The caloric capacity of the calorimetric system with each cell was determined by electrical calibration; the result was used in the experimental evaluation of municipal solid waste caloric value.